Abrading apparatus



May 29, 1951 F. F. KLETTl 2,554,830

ABRADING APPARATUS Filed Sept. 25, 1946 2 Sheets-Shet 1 swam/I07,

Free I? K/e Z t May 29, 1951 KLETT 2,554,830

ABRADING APPARATUS Filed Sept. 25, 1946 2 Sheets-Sheet 2 Patented May 29', 1951 U N I TED STATES PATENT F F LICE 2,554,830 V ABRADING APPARATUS I Fred F. Klett, New Hope, Pa., assignor *to Amer 'ican Lava Corporation, Chattanooga, -Tenn.-, a corporation of Tennessee Applicationseptember 25, 1946, Serial No. 6 9,fl 3 1 '12 Claims. 1

This invention relates generally to centerless grinding and particularly to apparatus for the centerless abradingorcutting of ceramic bodies. While the apparatus of the present invention is especially suited for use with ceramic bodies and will be so described for purposes of illustration, it will be evident that the invention has wide application in the centerless grinding art.

The manufacture of coil forms and-other'cylinder-like ceramic bodies for use as the insulating medium in radio coils and like applications has presented problems of unusual di'fii'ciilty. Such bodies aregenerally fired beforelbeing used and in this condition are too hard and brittle to be abraded effectively. They must therefore be cut or abraded to the desired shape before firing while still in a relatively soft state. At this stage a ceramic blank is easily chipped, thus making it impossible to grind the blank on a normal centering lathe. Resort has therefore been had to centerless grinding 'for profiling and cutting ceramic blanks.

The primary object of the present invention is to provide improved apparatus for the centerless grinding of ceramic blanks by which blanks can be profiled and cut to the desired shapes without chipping or other breakage.

Another object e'f'the invention is 'to provide improved apparatus for profiling and cutting ceramic blanks which can be adjusted for nandling blanks of uifierent size.

A further obj ect of the inventiohi's to provide improved apparatus for'profiling and cutting ceramic blanks which is automatic in operation and capable of handling blanks of uniform size as a continuous process.

Other objects and features of the-invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and illustratedin the accompanying drawings in which:

Figure 1 is a side elevational 'view of -a 'preferred embodiment of the invention showing the abrading apparatus mounted on a suitable support.

Figure 2 is an enlarged isometric view of the abrading apparatus.

Figure 3 is an enlarged side elevational view showing the details of'constructio'n of the blanksupporting drum and abrading wheels.

Figure 4 is a vertical sectional View taken along the lines 4-4 of Figure 3 with portions broken away and shown diagrammatically.

Figure 5 is a verticals ectional view taken along the lines 55 of Figure 3.

Figure "6 is an enlarged isometric 'view of the central portion of :Figure '2 illustrating in more detail the operation 0f "the apparatus.

Referring now in detail to the. drawings illustrating a preferred "embodiment of the invention, in which like reference characters designate like parts, numeral "I designatesa suitable table or "stand towhich is attached a base or frame '2. Mountedon 'the'bas'e are a pair of sup"- porting members or uprights 3 spaced longitudinally of the frame, each preferably comprising a pair of laterally spaced perpendicularly disposed pillars or posts 3a. Adjacent the upper ends of the posts and vertically adjustable rela tive thereto are :a :pair of collars "5 housing suitable bearings 6 in w-hich' ar'e carrie'd'theabrading wheel shaft 'or axle I, the latter mounting one or more abrading wheelsB. Thisshaf-t is adapted to be rotated at relatively high speed by a suitable motor #9 througha belto'r other connection lfl.

Mounted on the posts *4 :between the -'abrading wheel shaft 1 and the base and also vertically adjustable relative to the posts are collars H housing 'sl iitable bearings I2 in which are jour naledi a worksupporti ng shaf-t'or axle I 3. This shaft is disposed 'ldene'ath 'and parallel to the abradin'g wheel shaft 1 and intermediate the uprights 3 carries a drumier cylindrical carriage or cage 4' Wliiehis keyed or ether-wise affixed "to the shaft and rotatabie therewith.

As shown in the-drawings, the cage M may be formed by attaching, keying or otherwise, to the work-supporting shaft [3, a pair of spaced hubs 15, each carrying and formed integrally with a'star wheel 16. The peripheries of both of the star wheels 1'6 are slotted to provide a plurality'of pairs of spaced aligned slots ll. Each of these pairs "of slots is adapted to receive or seat bearings I 8 in which arejournaled the ends of the work=holding spindles, :rollers or shafts 1'9. These spindles, which form the; outside of the cage 14, are mounted parallel-to the axis of the work-supporting shaft 13, and designed to oper'ate adjacent to one another in such a manner as to 'ecc'entri'cally or e'xteriorly support a ceramic blankind icated diagrammatically at 20. The spindles may be secured 'or h'eld in the slots profiled. This they-accomplish by rotating With 3 the work-supporting shaft l3. At the same time it is essential that the blanks be rotated during the period in which they are in engagement with the abrading wheels 8. To perform both of these functions the spindles must rotate simultaneously about their own axes and the axis of the drum.

To obtain rotation of the spindles independently of the rotation of the shaft l3 there is'preferably provided a sun gear 22 mounted and freely rotatable on the shaft l3 adjacent one end of the cage [4. The sun gear is positioned to engage planetary gears 23 affixed to the adjacent ends of each of the spindles IS. The sun and planetary gears together form a gear train by which all of the spindles canbe rotated in the same direction and at the same speed independently of the rotation of the shaft [3.

The supporting shaft I3 is rotated by attaching to one of its ends, outwardly of the uprights 3, a worm 24 adapted to enmesh with a worm gear 25, the latter being driven through a sprocket and chain 26 or like connection by suitable motor 21. Actuation of the sun gear 22 by which the spindles are independently rotated may be accomplished by providing on its hub 28 a sprocket or spur gear 29 connected by a chain 30 or a like means to a suitable motor 3|. The abrading wheels 8 and spindles I9 are preferably rotated in the same direction and the cage I4 and the sun gear 22 inthe opposite direction, the abrading wheels at relatively high speed, the drum at a comparatively low speed and the sun gear actuating the spindles at a speed greater than that of the drum in order to impart the required independent rotation to the spindles.

While it is possible to support a ceramic blank directly on the spindles l9 there are preferably provided spaced collars, discs or rollers 32 on each of the spindles on which the blanks are directly supported. To ensure that the blanks remain seated on their respective pairs of spindles as they approach and engage the abrading wheels it is desirable to provide work-holding fingers 33 adapted to engage the ceramic blanks during this portion of their travel. These fingers may be attached to the uprights 3 by appropriate means such as the hanger 34, the latter preferably being swingably attached to collars 4 carried by and vertically adjustable relative to the uprights 3 to enable clearance between the fingers and the spindles to be adjusted to accommodate blanks of different size.

The ceramic blanks from which the final coil forms or other insulating bodies are formed may be fed to the abrading apparatus by hand or from an appropriate feeding trough. In either case each blank is deposited on adjacent spindles just prior to the time when the latter enters the are included by the fingers. The blanks are continuously fed into spaces between adjacent spindles as the latter reach the feeding point. After the blanks have passed under the abrading wheels and there have been profiled and cut to the desired configuration and size, they drop off into the outlet chute 35 which may be attached to the hanger 34 supporting the fingers 33. Through this chute the formed bodies are led from the apparatus.

As previously mentioned, both the abrading wheels 8, the fingers 33 and the drum H! are independently adjustable vertically on the uprights 3. Thus the apparatus is enabled to handle ceramic blanks of different sizes and make cuts of dififerent depths by adjusting the abrading wheels and fingers vertically relative to the drum to provide the desired spacing therebetween. In the illustrated embodiment the two abrading wheels in the position shown are set to cut a blank to a particular length. Any desired profiling or variations in cutting can of course be obtained by changing the setting as well as the number and configuration of the abrading wheels.

In addition to the vertical adjustment it may also'be necessary to vary the speed of rotation of the drum with different size blanks to afford time for the abrading wheels to complete their profiling and cutting. As has been pointed out heretofore, sufficient time for these operations will normally be allowed by turning the drum at a low speed relative to that of the abrading wheels. However, in some instances it may be desirable to cause the drum to dwell as each blank reaches abrading position, in which case an appropriate time-controlling device 36 can be attached to the apparatus to cause the drum to stop at predetermined intervals. The other rotating members of the apparatus, the spindles l 8 are rotated in the same direction as the abrading wheels 8 and at such relative speed that the peripheral speeds of the wheels and the blanks will be different, thus providing for most efiicient abrading.

From the above detailed description it will be apparent that there has been provided an improved apparatus of rugged construction particularly adapted for the cutting and profiling of ceramic blanks as a continuous operation. While a single embodiment of the apparatus has been illustrated and described it will be understood that this embodiment is merely exemplary of the invention and that all modifications are intended to be included that depart neither from the spirit of the invention nor the scope of the appended claims.

I claim:

1. Abrading apparatus comprising a rotatable drum, a plurality of blank-holding spindles rotatably mounted around the periphery of said drum and rotatable therewith, a rotary abrading wheel associated with said drum, said spindles being adapted to eccentrically support work blanks and move said blanks into engagement with said abrading wheel, and means for rotating said spindles independently of said drum and turning said blanks while the latter are in engagement with said abrading wheel.

2. Abrading apparatus comprising spaced uprights mounted on a base, an abrading wheel mounted on a shaft rotatably carried by said uprights and vertically adjustable relative thereto, a drum rotatably mounted on said uprights beneath said abrading wheel, a plurality of blankholding spindles rotatably mounted around the periphery of said drum and rotatable therewith, adjacent of said spindles being adapted to move a blank into engagement with abrading wheel, means for rotating said abrading wheel and drum, and means for rotating said spindles independently of said drum and turning said blanks while the latter are in engagement with said abrading wheel.

3. Abrading apparatus comprising a rotatable drum, a plurality of blank-holding spindles rotatably mounted around the periphery of said drum and rotatable therewith, a rotary abrading wheel associated with said drum, means for rotating said abrading wheel and drum, adjacent of said spindles cooperating to move a blank into engagement with said wheel on rotation of said drum, means for rotating said spindles independently of said drum and turning said blanks while the latter are in engagement with said abrading wheel, and means for varying the clearance between said spindles and said abrading wheel.

4. Abrading apparatus comprising a rotatable drum, a plurality of blank-holding spindles rotatably mounted around the periphery of said drum and a rotary abrading wheel associated with said drum, said spindles being adapted to eccentrically support said blanks and move said blanks into engagement with said abrading wheel on rotation of said drum, means for rotating said abrading wheel at a relatively high speed, means for rotating said drum at a relatively low speed, and means for rotating said spindles independently of said drum and turning said blanks at a peripheral speed different from that of said abrading wheel.

5. Abrading apparatus comprising an abrading wheel, a drum mounted on an axis parallel to the axis of said wheel, means for rotating said wheel and drum at relatively different speeds, a plurality of pairs of blank-holding spindles rotatably mounted on said drum, each of said pairs of spindles cooperating to move a blank into engagement with said abrading wheel on rotation of said drum, a resilient finger associated with said drum and adapted to maintain said blanks in position on said spindles, and means for rotating said spindles independently of said drum and turning said blanks while the latter are in engagement with said abrading wheel.

6. Abrading apparatus comprising an abrading wheel, a drum mounted on an axis parallel to the axis of said wheel, means for rotating said wheel and drum at relatively different speeds, a plurality of blank-holding spindles rotatably mounted on said drum, adjacent of said spindles cooperating to move blanks into engagement with said abrading wheel on rotation of said drum, a resilient finger associated with said drum and adapted to maintain said blanks in position on said spindles, means for rotating said spindles independently of said drum and turning said blanks while the latter are in engagement with said abrading wheel, and means for varying the clearance between said spindles and said abrading wheel.

7. Abrading apparatus comprising a shaft rotatably mounted between a pair of spaced uprights and carrying an abrading wheel, a drum rotatably mounted on said uprights beneath said abrading wheel, a plurality of blank-holding spindles rotatably mounted around the periphery of said drum, adjacent of said spindles being adapted to move a blank into engagement with said abrading wheel, means for rotating said abrading wheel, means for interruptedly rotating said drum causing said blanks to dwell beneath said abrading wheel, and means for rotating said spindles independently of said drum and turning said blanks while the latter are in engagement with said abrading wheel, said shaft being vertically adjustable relative to said drum for varying the clearance between said abrading wheel and said spindles.

8. In an abrading apparatus a rotatable carriage, means rotatably mounted on said carriage and rotatable therewith for exterially supporting work on an exterior of said means and means for rotating said supporting means and thereby turning said work relative to said carriage.

9. In an abrading apparatus a rotatable carriage, a plurality of spindles rotatably mounted on said carriage and rotatable therewith on rotation therewith, adjacent of said spindles cooperating to support and hold a work blank, and means for rotating said spindles independently of the rotation of said carriage and thereby turning said blank.

10. Abrading apparatus comprising a rotatable drum, a rotatable abrading wheel associated with said drum, means for rotating said drum and abrading wheel, supporting means rotatably mounted about the periphery of said drum and rotatable therewith on rotation of said drum, said supporting means supporting work on an exterior thereof, and means for rotating said supporting means, and thereby turning said work relative to said drum on presentation of said work to said abrading wheel.

11. Abrading apparatus comprising a rotary abrading wheel, a carriage spaced from and rotatable on an axis parallel to the axis of said wheel, a plurality of spindles rotatably mounted on said carriage and rotatable therewith on rotation thereof, adjacent of said spindles cooperating to support and hold a work blank in engagement with said abrading wheel, and means for rotating said spindles independently of the rotation of said carriage, and thereby turning said blank.

12. Abrading apparatus comprising a shaft carrying an abrading wheel, a drum rotatable about an'axis parallel to the axis of said shaft, a plurality of spindles rotatably mounted around the periphery of said drum and rotatable therewith, said spindles being adapted to support blanks on exteriors of said spindles and to move said blanks into abrading wheel engaging position, and means for rotating said spindles, and thereby turning said blanks relative to said spindles and drum while said blanks are in wheel engaging position.

FRED F. KLETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,186,203 Jeffery et a1 June 6, 1916 1,255,693 Bell Feb. 5, 1918 1,974,696 Swanson Sept. 25, 1934 2,363,448 Siesel Nov. 21, 1944 

